Pension Plan (Components Of Net Periodic Benefit Expense) (Details) - USD ($) $ in Thousands	3 Months Ended		9 Months Ended
	Sep. 30, 2017	Sep. 30, 2016	Sep. 30, 2017	Sep. 30, 2016
Defined Benefit Plan, Net Periodic Benefit Cost (Credit) [Abstract]
Service cost	$ 1,317	$ 1,264	$ 3,951	$ 3,792
Interest cost	1,271	1,217	3,813	3,651
Expected return on plan assets	(2,863)	(2,737)	(8,589)	(8,211)
Amortization of prior service cost	0	0	0	0
Recognized net actuarial loss	144	193	432	579
Benefit expense	(131)	(63)	(393)	(189)
Pension plan contributions	$ 0	$ 0	$ 0	$ 0